WHAT IS THE REVISED NIOSH LIFTING EQUATION?

LC x HM x VM x DM x AM x FM x CM = RWL

where LC is the load constant (23 kg) and other factors in the equation are:HM, the Horizontal Multiplier factorVM, the Vertical Multiplier factorDM, the Distance Multiplier factorFM, the Frequency Multiplier factorAM, the Asymmetric Multiplier factorCM, the Coupling Multiplier factorRWL, the Recommended Weight Limit 

Horizontal Multiplier (HM)Vertical Multipler (VM)

H = Horizontal Distance (cm)

HM Factor

25 or less 1.00 

30 0.83

40 0.63

50 0.50

60 0.42

V = Starting Height (cm) VM Factor

0 0.78

 30   0.87

 50  0.93 

 70   0.99 

 100   0.93 

 150   0.78 

 175  0.70

 >175  0.00

Distance Multipler (DM) Asymmetric Multipler (AM)

D = Lifting Distance (cm) DM Factor

25 or less 1.00

 40   0.93 

 55   0.90

 100   0.87 

 145  0.85 

 175  0.85

 >175  0.00

A = Angle (degrees) AM Factor

90°  0.71 

 60°   0.81

 45°   0.86 

 30°  0.90

 0°  1.00

Frequency Multipler (FM): The frequency (F) of lifts and the duration of lifting (in minutes or seconds) over a workshift

F = Time Between Lifts 

FM Factor

Lifting While Standing: OR Lifting While Stooping:

One Hour or Less

Over One Hour

One Hour or Less

Over One Hour

5 min 1.00 0.85 1.00 0.85

1 min  0.94 0.75 0.94 0.75

30 sec 0.91 0.65 0.91 0.65

15 sec 0.84 0.45 0.84 0.45

10 sec 0.75 0.27 0.75 0.27

6 sec 0.45 0.13 0.45 -

5 sec 0.37  - 0.37  -

. 

Coupling Multipler (CM): The quality of grasp (or coupling, C)

C = GraspCM Factor:

Standing Stooping

Good (handles) 1.00 1.00

Fair 1.00 0.95

Poor 0.90 0.90